Question 1

A Decision Tree is a is a visual decision making tool that can prove useful across a number of business settings. Decision trees provide all of the following EXCEPT:

Accepted Answer

Decision trees do not provide comprehensive risk analysis.
Key Takeaway: A decision tree is a visual decision making tool that can prove useful across a number of business settings. The main principle behind a decision tree is the presentation and comparison of a number of competing alternatives. It also provides potential outcomes and their probabilities.

Question 2

The following is a multiple regression model. What do the regression coefficients b1 and b2 represent? Y_i = b₀ + b₁X_1i + b₂X_2i+e_i

Accepted Answer

Regression coefficients b₁ and b₂ in a linear regression model represent slopes of the independent variables under study. Key Takeaway: Multiple regression analysis is used to study the effect of two or more independent variables on the dependent variable. In the linear regression model, b₁ and b₂ are calculated slopes of the independent variables. For example, if a marketing researchers is studying income and level of education as independent variables, their slopes in the analysis would be represented as b₁ and b₂.

Question 3

A process is a:

Accepted Answer

A process is a value-added transformation from input to output.
Key Takeaway: A process is designed to transform input into output that adds value. For example, a statistical tools transforms raw data into patterns and trends that add value to a business operation. Similarly, a manufacturing tool transforms raw materials into usable, value-added goods.

Question 4

The ability of an electronic scale to measure substances consistently every time the measurement is made is referred to as _____________.

Accepted Answer

Precision is the ability of an electronic scale to measure substances consistently every time the measurement is made.
Key Takeaway: Precision in measurement systems analysis is an important test of how well measuring equipment can consistently take readings. For example, if an electronic chemical is used to measure the weights of minute substances, the scale must provide consistent readings every time the measurement is made. An imprecise machine does not provide trustworthy measurements. To check for precision, multiple readings of the same materials are taken and the deviations of one reading from the others are measured.

Question 5

_____ is a tool that is used in the define phase of Six Sigma DMAIC, and can be used in developing high level process maps in a process improvement project.

Accepted Answer

SIPOC is a tool that is used in the define phase of Six Sigma DMAIC.
Key Takeaway: A SIPOC diagram is a graphical tool used by managers to show all important components of a process improvement project before initiation. SIPOC is short for Suppliers, Inputs, Process, Outputs, and Customers. The major goal of SIPOC analysis is to define a complex project that may not be well scoped, and is typically employed at the define phase of the Six Sigma DMAIC methodology.

Question 6

Real estate agents at a national agency meet on a weekly basis to discuss property pricing. With repossessed homes, the proper procedure for pricing is for three real estate agents to agree on a selling price. This is an example of ____________.

Accepted Answer

Percent agreement is used in measurement systems analysis to provider inter-rater agreement.
Key Takeaway: Percent agreement is a methodology used in measurement systems analysis to provider inter-rater agreement. In this example, after the review of current housing prices in similar conditions and under similar repossession, agreement amongst real estate agents must be reached before appraisal is adopted.

Question 7

Workers in the overnight shift at an assembly line, on average, require 8.5 minutes to complete once production cycle. Production managers have contributed this to biological differences in overnight reaction times. What type of variation is this an example of:

Accepted Answer

Inherent variation is process variation that exists naturally.
Key Takeaway: Process variations that exist naturally include nocturnal differences in human performance. If workers in the overnight shift consistently require a longer period of time to complete one production cycle, regardless of skills, staffing and machine performance, then this is considered to be inherent variation.

Question 8

The following are examples of statistical process control charts EXCEPT:

Accepted Answer

P-charts, C-charts, and Xbar charts are all examples of statistical process control charts.
Key Takeaway: A P-chart is used to illustrate proportions while a C-chart is used when counting the number of nonconformities in an area of opportunity. Xbar charts are used measuring numeric data such as means.

Question 9

Project specification limits are set by managers in response to customers' expectations. The largest specification value that can be obtained and still be acceptable to customer expectations is referred to as:

Accepted Answer

The largest specification value that can be obtained and still be acceptable to customer expectations is referred to as USL.
Key Takeaway: Upper Specification Limit (USL) is the largest specification value that can be obtained in a process and still be acceptable to customer specifications. For example, if a client expects no more than 4 defects to can shapes from a factory per 1000, then the USL is 4.

Question 10

The Cp index is a measure of potential process performance as seen in the equation below. What does a Cp value greater than 1 imply?
Cp = USL - LSL/ 6( Rbar/d2) = specification spread/process spread

Accepted Answer

In an assessment of potential process performance, a Cp value greater than 1 implies that a process has the potential of having > 99.73% of outcomes within specifications .
Key Takeaway: A large specification spread means that customer requirements are broad. In other words, the range between the lower specification limit and the lower specification limit is large. This means that the process performance can lead to a production of outcomes that encompass more than 99.7% of customer specifications.

Question 11

The Six Sigma approach allows for a shift of as much as ______ standard deviations, so it is essentially a ±4.5 standard deviation goal.

Accepted Answer

The Six Sigma approach allows for a shift of as much as 1.5 standard deviations.
Key Takeaway: The Six Sigma approach is concerned with the number of sigmas that will fit between the process mean and the nearest specification limit. A process that fits 6 sigmas between a mean and its nearest specification limit in the short term will experience a 1.5 shift that will result in only 4.5 sigmas fitting.

Question 12

Ron's research team is examining the tread quality of their company's new tires. The team decides to use a factorial design that is examining 2 types of tread in 3 different types of metal installations. What type of design is this?

Accepted Answer

The above experimental design is a 2X3 factorial design.
Key Takeaway: Factorial design is a type of experimental design whereby 2 or more factors are studied, each with a number of levels. In this example, the tire treads are the factors while the metal installations are the levels. This type of design allows for a comparison of factors while examining for interaction effects between factors and levels.

Question 13

A C_p of more than 2 implies that a process has the potential of _____________ expectations of Six Sigma standards.

Accepted Answer

A C_p of more than 2 implies that a process has the potential of meeting expectations of Six Sigma standards. Key Takeaway: A C_p of more than 2 implies that a specification spread is significantly larger than a process spread. A large specification limit allows for fewer errors to be made during a manufacturing or a business process. For example, if a machine produces snow shovels of a large specification spread, the likelihood of producing shovels that do not meet customer requirements are smaller than one with a small specification spread.

Question 14

A hotel manager wishes to compare packaged deals to frequent guests. Specifically, he is interested in whether those who receive business deals stay longer than those who receive personal deals. What statistical test is most appropriate to compare the two deals?

Accepted Answer

An F test is the most appropriate statistical test to compare the two deals.
Key Takeaway: An Analysis of Variance (ANOVA) provides a comparison of the means between 2 or more groups. ANOVA's F test looks at the variation within groups and between groups and examines whether there is a statistically significant difference between the means of the groups.

Question 15

Statistical Process Control (SPC) is an application of statistical methodology such as experiments to ensure that a process produces desired effects. SPC can be broken down into understanding the following factors EXCEPT:

Accepted Answer

Statistical Process Control (SPC) can be broken down into understanding the process, the causes of variation, and corrective measures.
Key Takeaway: SPC is an application of statistical methodology such as control charts and designed experiences to control processes. SPC is designed to explore the causes of variation in process outputs such as common and special variations as well as ways to provide corrective measures.

Question 16

In Total Quality Management, most variation in a process is due to the system not the individual. Is this statement true?

Accepted Answer

In Total Quality Management, most variation in a process is due to the system not the individual.
Key Takeaway: In Total Quality Management (TQM), most variation occurs because of the system in place (through processes) and not the individual. For example, the most common causes of variation occurs because of procedural issues, environmental issues, materials, and machines. Managers interested in providing quality products or services to customers must explore the sources of variation in processes.

Question 17

In an effort to mobilize resources needed for the annual fundraising campaign, Stewart uses a specialized type of bar chart to track the project's milestones within important phases. What is this type of bar chart referred to?

Accepted Answer

A Gantt chart is a specialized type of bar chart to track a project's milestones.
Key Takeaway: A Gantt is a project organization tool that is based on the complex use of bar charts. The goal of using a Gantt chart is to track a project's important phases such as initiation, outlining milestones within each phase. A well-constructed Gantt chart will keep track of a project's schedule and activities as outlined in the work breakdown structure.

Question 18

In Six Sigma methodology implementation within a company, the commitment of senior management and executives is important because:

Accepted Answer

In Six Sigma methodology implementation within a company, the commitment of senior management and executives is important because they are important in providing resources and support.
Key Takeaway: The commitment of senior management and executives is important in implementing Six Sigma methodology throughout an organization as they provide important resources and support. The resources important to successful Six Sigma implementation are adequate time and support to Six Sigma champions and others including those with Green Belt and Black Belt certification. Since much of their work involves collecting and analyzing data, the cooperation of all employees at each level can only be enforced if an organization-wide imperative is set.

Question 19

A local FedEx company wishes to reduce the penalties incurred from late deliveries to business centers. Managers conduct the following analysis to understand the root cause of these late deliveries:

Accepted Answer

Managers conduct time trap analysis to understand the root cause of late deliveries.
Key Takeaway: Time trap analysis provides calculations on where delays in a particular process occur. The goal of such analysis is to understand where, in a multistep process such as that of delivering packages to addresses, do delays occur and how they can be reduced or eliminated. Often, a time trap analysis would show redundancies in process elements.

Quiz 2: Six Sigma Green Belt